JP2005128453A - Information rewritable label, information storage medium, and information recording and reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information rewritable label to and from which label information can be repetitively written and erased without provision of specific apparatus for printing of the rewriting label. <P>SOLUTION: The information rewritable label is an information rewritable label for an optically, magnetically or electrically recorded information storage medium and is provided with a color developing layer containing one or a plurality of photochromic compounds as the color materials constituting the label on a substrate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an information rewritable label for an information storage medium, an information storage medium using the label, information rewriting means for the label, and an information recording / reproducing apparatus using the label.

  Conventionally, storing music information and video information on a rewritable optical disk has been widely performed. Also, it is a common practice to attach a label on which a music or video title is displayed after recording or rewriting to the disc so that the contents can be understood at a glance. Usually, this label is pasted on an optical disc after a title is written on a label sheet dedicated to the optical disc or printed by a printer.

However, in the conventional method, it is necessary to take time and effort to replace the label every time the recorded information is rewritten. As a method to save this trouble, a label provided with an organic compound that can be developed and erased by heat is attached to a recording medium of an optical disk or a floppy (R) disk, and information on the recording medium is reversible using a thermal printer head (R). Japanese Patent Laid-Open No. 7-130132 (Patent Document 1) proposes a printing method. However, since the rewritable display medium disclosed in Patent Document 1 uses a thermal printer head as a printing means, a printer for printing is required separately from the optical disc drive main body. In addition, since an organic compound that can be developed and decolored by heat is used as a color material for the label, there is a problem that it is difficult to display a multi-color or full-color label.
JP-A-7-130132

The present invention is based on the above problems of the prior art.
An object of the present invention is to provide a label for an information recording medium such as an optical disc capable of repeatedly writing and erasing label information without providing a special device for printing the label.
Another object of the present invention is to provide an apparatus for an information recording medium such as an optical disc that can repeatedly write and erase information on the label of the optical disc without providing a special printing mechanism for printing the label. To do.
Another object of the present invention is to provide a label for an information recording medium such as a multi-color or full-color rewritable optical disk.
The present invention also provides an apparatus for an information recording medium such as an optical disc that can repeatedly write and erase multi-color or full-color information on an optical disc label without providing a special printing mechanism for printing the label. The purpose is to do.

According to the present invention, the following information rewritable label, information rewriting means for the label, and an information recording / reproducing apparatus are provided.
[1] An information rewritable label for an information storage medium recorded optically, magnetically, or electrically, and a coloring layer containing one or more kinds of photochromic compounds as a coloring material constituting the label A rewritable label characterized in that is provided on a substrate.
[2] The information rewritable label according to [1], wherein the hue of the photochromic compound is changed by irradiation with light of a specific wavelength, and the hue is restored by irradiation with light of another specific wavelength.
[3] The information rewritable label according to [1] or [2], wherein the photochromic compound is composed of three types of photochromic compounds having different color hues.
[4] The three types of photochromic compounds are a first photochromic compound having a maximum absorption wavelength in a color development state of 400 nm or more and less than 500 nm, and a second photochromic compound having a maximum absorption wavelength in a color development state of 500 nm or more and less than 600 nm. The information rewritable label according to [3], wherein the photochromic compound is a third photochromic compound having a maximum absorption wavelength in a colored state in a range of 600 nm to less than 700 nm.
[5] The information rewritable label according to [3] or [4], wherein the maximum absorption wavelength in the decolored state of the three types of photochromic compounds is 400 nm or less.
[6] An information storage medium that is integrated with the information rewritable label according to any one of [1] to [5].
[7] Information rewriting means for a label, wherein a character or a picture is formed on the information rewritable label according to any one of [1] to [5] using irradiation light from a light source .
[8] The information rewriting means for the label according to [7], wherein a plurality of light sources are used.
[9] The information rewriting means for the label according to [8], wherein at least one of the plurality of light sources is a light source that emits ultraviolet rays.
[10] In order to record or reproduce information on an information recording medium, the information rewriting means for the label according to [8] or [9] is provided, and at least one of a plurality of light sources constituting the rewriting means An information recording / reproducing apparatus that is also used as a light source.
[11] The information rewriting means to the label according to [8] or [9] is provided, and at least two of the plurality of light sources constituting the rewriting means record or reproduce information on the information recording medium. An information recording / reproducing apparatus characterized in that it is also used as a light source.
[12] Forming characters and pictures on the information rewritable label by setting the surface opposite to the information recording surface of the information recording medium described in [6] to the information recording / reproducing apparatus The information recording / reproducing apparatus according to [9] or [10], wherein

The invention according to claim 1 of the present invention can provide a label for an information recording medium that can be rewritten using light by using a photochromic compound as a coloring material of the rewritten label.
The invention according to claim 2 of the present invention is an information recording which can be rewritten using only light by changing the hue by irradiation with light of a specific wavelength and returning the hue by irradiation with light of another specific wavelength. Media labels can be provided.
The invention according to claim 3 of the present invention can provide a full-color label for an information recording medium by using three types of photochromic compounds having different color hues as the photochromic compound.
The invention according to claim 4 includes a first photochromic compound having a maximum absorption wavelength in the range of 400 nm to less than 500 nm, a second photochromic compound having a maximum absorption wavelength in the range of 500 nm to less than 600 nm, and color development. By using the third photochromic compound having a maximum absorption wavelength in the range of 600 nm or more and less than 700 nm, a full color information recording medium label having a wide hue range can be provided.
The invention according to claim 5 of the present invention is characterized in that the three types of photochromic compounds have a maximum absorption wavelength in the decolored state of less than 400 nm, whereby a rewritable label having no color in the decolored state can be provided.
Since the information storage medium according to the sixth aspect of the present invention is integrated with the information rewritable label, the label display can be rewritten using light, and the label display can be made full color. .
The invention according to claim 7 of the present invention does not require the writing head and the rewrite label to be in close contact with each other by using the light irradiation means as the means for forming characters and pictures on the rewrite label.
The invention according to claim 8 of the present invention can provide means for rewriting using only light by using a plurality of light irradiation means as means for forming characters and pictures on the rewrite label.
The invention according to claim 9 of the present invention can simultaneously develop a plurality of photochromic compounds by using ultraviolet light irradiation as one of the light irradiation means.
In the invention according to claim 10 of the present invention, the label of the optical disk can be rewritten without providing a special device for rewriting the label by using both the light source for recording and reproduction and the light source for rewriting the label.
According to the eleventh aspect of the present invention, two or more light sources for rewritable labels are also used as light sources for recording or reproducing information on an information recording medium, thereby providing no special light source for rewriting labels. The label on the optical disc can be rewritten.
The invention according to the twelfth aspect of the present invention is characterized in that a character or a picture can be formed on a rewritable label by setting the surface opposite to the information recording surface of the information recording medium in the information recording / reproducing apparatus. An optical disk label can be rewritten without providing a mechanism.

Hereinafter, the present invention will be described in detail.
The information rewritable label of the present invention is used for an information rewritable label (hereinafter also simply referred to as a rewritable label) for an information storage medium recorded optically, magnetically or electrically. For example, as shown in FIG. 1, the rewritable label 2 of the present invention is used integrally with an information storage medium (in this case, the optical disc 1). Such a rewritable label is conventionally known, but a feature of the present invention is that a coloring layer containing one or more kinds of photochromic compounds is provided on a substrate as a color material constituting the rewritable label. Since the photochromic compound is a reversible display material that reversibly develops color when irradiated with light, information can be rewritten using light in the rewritable label of the present invention by using the photochromic compound.

The photochromic compound used in the present invention has a feature that the hue changes by light irradiation of a specific wavelength, and the hue returns to the original state by light irradiation of another specific wavelength. In particular, a photochromic compound that reversibly loses color is characterized by being colored by ultraviolet light and decolored by visible light. Therefore, a rewrite label using a photochromic compound can be rewritten using only light.
Such a photochromic compound is described in detail in Japanese Patent Application No. 14-251429 filed earlier by the present applicant.

  The photochromic compound is preferably composed of three types of photochromic compounds having different color hues. When three types of photochromic compounds are used, a full color can be displayed.

  Furthermore, the above three types of photochromic compounds are a first photochromic compound having a maximum absorption wavelength in the range of 400 nm to less than 500 nm in a colored state, and a second photochromic compound having a maximum absorption wavelength in the range of 500 nm to less than 600 nm. Preferably, the compound is a third photochromic compound having a maximum absorption wavelength in a colored state of 600 nm or more and less than 700 nm. When such a photochromic compound is used, a rewritable label for a full color information recording medium having a wide hue range can be provided.

  The first photochromic compound having a maximum absorption wavelength in the color development state in the range of 400 nm or more and less than 500 nm is a yellow color development material, and the second photochromic compound in the color development state having a maximum absorption wavelength in the range of 500 nm to less than 600 nm is A third photochromic compound that is a magenta color developing material and has a maximum absorption wavelength in a color developed state in the range of 600 nm to less than 700 nm is a cyan color developing material. By using three types of photochromic compounds that develop colors of Y (yellow), M (magenta), and C (cyan) at the time of color development as color materials, it is possible to display full-color and wide hue range colors.

  Furthermore, in the present invention, the maximum absorption wavelength in the decolored state of the above three types of photochromic compounds is preferably in the ultraviolet region of 400 nm or less because white can be obtained during decoloring. When all three types of photochromic materials are colored, black is displayed because light in all the wavelength regions of Y (yellow), M (magenta), and C (cyan) is absorbed. Further, blue is displayed when only the yellow coloring material is erased, green is displayed when only the magenta coloring material is erased, and red is displayed when only the cyan coloring material is erased. Further, when all three types of photochromic materials are decolored, the color becomes white, and a full color hue can be obtained by combining the decoloration degree of these three types of photochromic materials. In addition, since the photochromic material used in the present invention has a feature that the color development and decoloration can be controlled by light, it has a feature that it is not necessary to closely contact the writing head and the rewriting label as in thermal recording and magnetic recording. .

In the rewritable label of the present invention, the color developing layer containing the photochromic compound described above is provided on the substrate.
The color developing layer is preferably made of a mixture of a photochromic compound and a resin. By mixing the photochromic compound and the resin, the photochromic compound can be uniformly applied.

  The resin is not particularly limited, but polystyrene, polycarbonate, polymethyl methacrylate and the like are preferable. The blending amount of the photochromic compound and the resin is preferably 1: 100 to 10: 1 by weight, more preferably 1:20 to 2: 1, and still more preferably 1:10 to 1: 1. When the proportion of the photochromic compound is too small, there is a possibility that an appropriate color density cannot be obtained at the time of color development, and when the proportion of the photochromic compound is too large, there is a possibility that it cannot be uniformly applied.

  In the color developing layer, a dye other than the photochromic compound for producing the background color of the label can be added as long as the object of the present invention is not impaired.

The coloring layer is formed by dipping, blade coating, spin coating, printing, or the like.
The thickness of the coloring layer is preferably from 0.01 to 100 μm, more preferably from 0.1 to 10 μm, still more preferably from 1 to 5 μm. If the layer is less than 0.01 μm, an appropriate concentration may not be obtained at the time of color development, and if it exceeds 100 μm, the display label may be cracked.

Although there is no restriction | limiting in the base | substrate which comprises the rewritable label of this invention, For example, a white plastic film and white plain paper are mentioned.
Further, the thickness of the substrate is preferably 0.01 to 1 mm, more preferably 0.05 to 0.5 mm, and still more preferably 0.1 to 0.3 mm. If the thickness of the substrate is less than 0.01 mm, the label may be broken, and if it exceeds 1 mm, it may be difficult to attach the label.

  In the present invention, it is preferable to provide a protective layer on the color forming layer. Examples of the material constituting the protective layer include polyvinyl alcohol, silicone resin, and acrylic resin. Among these, polyvinyl alcohol is preferable in terms of barrier properties against oxygen and easy application.

The protective layer is formed by a coating method such as dipping or blade, a spin coating method, or a printing method.
The thickness of the protective layer is preferably from 0.01 to 100 μm, more preferably from 0.1 to 20 μm, still more preferably from 1 to 10 μm. When the layer is less than 0.01 μm, there is a possibility that it does not serve as a protective layer from the viewpoint of wear resistance and gas barrier properties, and when it exceeds 100 μm, there is a possibility that the display label may crack.

  The information storage medium of the present invention is integrated with the above-described information rewritable label, and the label display can be rewritten using light, and the label display can be made full color. . A typical example of the information storage medium is an optical disk. As a means for integration, a method is generally used in which an adhesive is applied to the back surface and a substrate having a photochromic compound formed on the front surface is attached to the disk surface.

Next, information rewriting means for information rewritable labels according to the present invention will be described.
In the rewriting means, characters and pictures are formed on the rewriting label using irradiation light from a light source. Therefore, it is not necessary to bring the writing head and the rewrite label into close contact with each other, so that an image with high resolution can be repeatedly formed without causing mechanical damage to the label.

In the rewriting means of the present invention, it is preferable to use a plurality of light sources. When a plurality of light irradiation means are used as means for forming characters and pictures on the rewrite label, rewriting can be performed using only light. This is because the photochromic compound has a property that the hue is changed by irradiation with light of a specific wavelength, and the hue is restored by irradiation with light of another specific wavelength.
Furthermore, it is more preferable that at least one of the plurality of light sources is a light source that emits ultraviolet rays. By using ultraviolet light irradiation as one of the light irradiation means, a plurality of photochromic compounds can be colored simultaneously. Further, when the wavelength of the light used for changing the hue matches the wavelength of the light source used for recording / reproducing of the optical disc, a further advantage arises.

  For example, in a third photochromic compound having a maximum absorption wavelength in a colored state in the range of 600 nm to less than 700 nm, indole fulgide-based photochromic compounds and diarylethene-based photochromic compounds are known as photochromic compounds having absorption at a wavelength of 780 nm in the colored state. ing. When these photochromic compounds are used as a coloring material for a rewritable label, it is possible to develop a color with ultraviolet rays and erase the color with a light source near 780 nm for recording or reproducing information on a CD. As a photochromic compound having absorption at a wavelength of 660 nm in a colored state in a third photochromic compound having a maximum absorption wavelength in a range of 600 nm or more and less than 700 nm in a colored state, a pyrrolfrugide-based photochromic compound is known. When these photochromic compounds are used as a coloring material for a rewritable label, it is possible to develop a color with ultraviolet rays and to erase the color with a light source near 660 nm for DVD information recording or reproduction.

Next, the information recording / reproducing apparatus of the present invention will be described.
One information recording / reproducing apparatus of the present invention comprises information rewriting means for the rewrite label, and at least one of a plurality of light sources constituting the rewriting means for recording or reproducing information on an information recording medium. Also used as a light source. Therefore, it is possible to rewrite the label of the information storage medium without providing a special device for rewriting the label. Examples of the apparatus of the present invention include an apparatus for recording or reproducing information using a laser such as an optical disk.

Furthermore, another information recording / reproducing apparatus of the present invention further comprises means for rewriting information on the rewritable label, and at least two of a plurality of light sources constituting the rewriting means record or reproduce information on the information recording medium. It is also used as a light source. Therefore, the label of the optical disk can be rewritten without providing a special light source for rewriting the label.
Next, a specific description will be given of the fact that two or more light sources serve both as a means for writing on the rewritable label and a means for recording or reproducing information on the information recording medium.

  Recent optical disc apparatuses are widely equipped with light sources of two types of wavelengths so that both CD and DVD optical discs can be recorded and reproduced. In particular, a Blu-ray disc, which is one of the next-generation DVD standards, is equipped with a 405 nm wavelength light source for Blu-ray discs and a 660 nm wavelength light source for DVDs as standard so that conventional DVD software can be seen. It is being considered. The pyrrole fulgide photochromic compound mentioned above as an example develops color with ultraviolet rays, but is known to develop with light of 405 nm. Therefore, if a pyrrole fulgide photochromic compound is used as a coloring material for a rewritable disc rewritable label, a rewritable optical disc rewritable label can be realized without using a special light source for the rewritable label. In order to realize a full-color rewritable label, an information recording / reproducing apparatus may be provided with an ultraviolet light source and a green light source having a wavelength in the vicinity of 550 nm in addition to the 405 nm and 660 nm light sources. As a result, the information recording / reproducing apparatus can be provided with an ultraviolet light source for coloring the photochromic compound and light for decoloring the photochromic compound colored in Y (yellow), M (magenta), and C (cyan). Furthermore, by setting the surface opposite to the information recording surface of the information recording medium in the information recording / reproducing apparatus, it is possible to form characters and pictures on the rewritten label without providing a special mechanism for rewriting the label. .

  In the information recording / reproducing apparatus of the present invention, a character or a picture is formed on the information rewritable label by setting a surface opposite to the information recording surface of the information recording medium toward the information recording / reproducing apparatus. It is preferable to do. When characters and pictures are formed on the rewritten label in this way, the label of the optical disk can be rewritten without providing a special mechanism for rewriting the label.

(Example 1)
2- [1- (1,2-Dimethyl-5-dimethylamino-3-indolyl) ethylidene] -3-isopropylidene succinic anhydride (hereinafter abbreviated as PC-1) as a photochromic compound that is decolored by light of 780 nm Was used.
PC-1 and polystyrene were mixed at a weight ratio of 1: 4 and dissolved in toluene, and then spin-coated on a white PET substrate having a thickness of 200 μm to form a coloring layer having a thickness of 2 μm. On top of that, a thin film of polyvinyl alcohol (thickness 2 μm) was applied as a protective layer to produce a CD rewrite label.

  It was confirmed that rewritable labels could be rewritten by irradiating them with an ultraviolet fluorescent lamp to develop cyan color and then partially erasing them using an infrared semiconductor laser having an oscillation wavelength of 780 nm.

(Example 2)
2- [1- (1-phenyl-2,5-dimethyl-3-pyrrolyl) ethylidene] -3-isopropylidene succinic anhydride (hereinafter referred to as a photochromic compound that develops color with 405 nm light and disappears with 660 nm light) (Abbreviated as PC-2).
PC-2 and polystyrene were mixed at a weight ratio of 1: 4 and dissolved in toluene, and then spin-coated on a white PET substrate having a thickness of 200 μm to form a coloring layer having a thickness of 2 μm. On top of that, a polyvinyl alcohol thin film (thickness: 2 μm) was applied as a protective layer to produce rewritable labels for DVDs and Blu-ray discs.

  It was confirmed that the obtained rewritable label could be rewritten by coloring with a blue semiconductor laser with an oscillation wavelength of 405 nm and then partially decoloring with a red semiconductor laser with an oscillation wavelength of 660 nm.

(Example 3)
2- [1- (5-Methyl-2-p-pyridyl-4-oxazolyl) ethylidene] -3-isopropylidene succinic anhydride (hereinafter abbreviated as PC-Y) was used as a photochromic compound exhibiting yellow color development.
2- [1- (2,5-dimethyl-3-thienyl) ethylidene] -3-isopropylidene succinic anhydride (hereinafter abbreviated as PC-M) was used as a photochromic compound exhibiting magenta color development.
2- [1- (1-Phenyl-2,5-dimethyl-3-pyrrolyl) ethylidene] -3-isopropylidene succinic anhydride (hereinafter abbreviated as PC-C) was used as a photochromic compound exhibiting cyan color development. PC-C has a maximum absorption wavelength at 630 nm in the colored state and has a maximum absorption wavelength in the ultraviolet region in the decolored state.

  PC-Y, PC-M, PC-C and polystyrene are mixed at a weight ratio of 1: 1: 1: 4, dissolved in toluene, spin-coated on a 200 μm-thick white PET substrate to a thickness of 2 μm. A coloring layer was formed. A full-color rewritable label was prepared by applying a polyvinyl alcohol thin film (thickness: 2 μm) as a protective layer thereon.

  The obtained replacement label is irradiated with an ultraviolet fluorescent lamp to develop a black color, and then partially erased using a blue semiconductor laser having an oscillation wavelength of 405 nm, a green semiconductor laser having an oscillation wavelength of 530 nm, and a red semiconductor laser having an oscillation wavelength of 660 nm. It was confirmed that the full color can be rewritten by coloring.

It is explanatory drawing of the information storage medium to which the label which can rewrite information was attached.

Explanation of symbols

1 Information storage medium 2 Label

Claims (12)

  An information rewritable label for an information storage medium that is optically, magnetically, or electrically recorded, wherein a coloring layer containing one or more kinds of photochromic compounds as a coloring material constituting the label is formed on the substrate. An information rewritable label characterized by being provided in.   The information rewritable label according to claim 1, wherein the hue of the photochromic compound is changed by irradiation with light of a specific wavelength, and the hue is restored by irradiation with light of another specific wavelength.   The information rewritable label according to claim 1 or 2, wherein the photochromic compound is composed of three types of photochromic compounds having different color hues.   The three types of photochromic compounds are a first photochromic compound in which the maximum absorption wavelength in a colored state is in a range of 400 nm to less than 500 nm, a second photochromic compound in which a maximum absorption wavelength in a colored state is in a range of 500 nm to less than 600 nm, 4. The information rewritable label according to claim 3, wherein the label is a third photochromic compound having a maximum absorption wavelength in a colored state in a range of 600 nm to less than 700 nm.   5. The information rewritable label according to claim 3, wherein the maximum absorption wavelength in the decolored state of the three types of photochromic compounds is less than 400 nm.   6. An information storage medium integrated with the information rewritable label according to claim 1.   6. Information rewriting means for a label, wherein a character or a picture is formed on the rewritable label according to any one of claims 1 to 5 using irradiation light from a light source.   8. The means for rewriting information on a label according to claim 7, wherein a plurality of light sources are used.   9. The information rewriting means for a label according to claim 8, wherein at least one of the plurality of light sources is a light source that irradiates ultraviolet rays.   The information rewriting means for the label according to claim 8 or 9 is provided, and at least one of a plurality of light sources constituting the rewriting means is also used as a light source for recording or reproducing information on an information recording medium. An information recording / reproducing apparatus.   The information rewriting means for the label according to claim 8 or 9 is provided, and at least two of the plurality of light sources constituting the rewriting means are also used as light sources for recording or reproducing information on the information recording medium. An information recording / reproducing apparatus.   7. A character or a picture is formed on the information rewritable label by setting the surface opposite to the information recording surface of the information recording medium according to claim 6 toward the information recording / reproducing apparatus. Item 11. The information recording / reproducing apparatus according to any one of Items 9 and 10.